FGSC #7200

Mutant Type

Genus: N

reporting_genes: Not available fl trp-3

species: Neurospora crassa

allele: P605 td24

stock: 2219

glasgow:

mutagen:

Depositor: DDP

Link Group: IIR IIR

MT: a

Species No: 10

gene_back:

oppmt: 0

trans:

ref1:

ref2:

site:

country:

ksudc_link: https://digital.lib.k-state.edu/item/neurospora-crassa/fgsc-7200

ksudc_link_html: https://digital.lib.k-state.edu/item/neurospora-crassa/fgsc-7200 ↗

Genes

Locus	Cultural Requirements	Link Group	Type
trp-3	IIR. Right of fl (2 to 6%). Left of rip-1 (9%) and un-5(10%) (816, PB). (1166). Uses tryptophan (685); strains carrying some alleles also use indole (4). Structural gene for tryptophan synthetase (1167), called tryptophan desmolase in early literature. Tryptophan synthetase catalyzes three reactions: indoleglycerol-phosphate -> tryptophan, indole tryptophan, and indoleglycerol-phosphate <-> indole (Fig. 11). In Neurospora, all three reactions are catalyzed by a single protein, which is specified by a single gene (645, 1167). Mutants lack indoleglycerol-phosphate -> tryptophan activity but differ with respect to the other activities; e.g., strains carrying trp-3 allele (td141 are blocked in indoleglycerol-phosphate utilization but can use indole; trp-3 (td100) can synthesize indole but not convert it to tryptophan; trp-3 (td140) lacks all three activities. (See references 582 and 1049 for citations and characteristics of other mutants.) Used extensively for studies of gene structure in relation to enzymatic activity (257, 582 and references therein, 1167). The active enzyme is a homooligomer (645) thought to have two domains (644 and references therein). Biochemical studies of complementation between alleles: in vivo (582, 583) and in vitro (1048 and references therein). Complementation maps (4, 5, 9 and references therein, 582). Fine-structure maps (5, 540, 582, 1049). Reviewed as example of gene fusion (218). trp-3 mutant C83 provided the first proved example in Neurospora of gene-controlled loss of enzyme activity (685); trp-3 mutant S1952 provided the first example of allele-specific suppression restoring functional wild-type-like enzyme (1166). Allele td140 is supersuppressible (954, 955). Certain classes of trp-3mutants are osmotic remediable (583). Called td and tryp-3.	IIR	B
fl	IIR. Between ace-1 (5 to 11%) and trp-3 (3%) (816, PB). (613)No macroconidia (609). Highly fertile (612). Used routinely as the female parent in tests for chromosome rearrangements and for mating type (e.g., reference 801). The flsingle mutant produces few microconidia when dry; when wetted, sufficient microconidia are produced to have been used in early irradiation and mutation studies (614, 915); large numbers can be obtained under certain conditions; see reference 893. pe fl (46, 700) and fl;dn (806) double mutants produce abundant microconidia; the latter combination is highly fertile when homozygous. Photograph of microconidial formation (774); see also reference 893. Nuclear numbers in microconidia (46, 64, 478). Wall analysis (207). Immunoelectrophoretic pattern (784). Paradoxical high alcoholic glycolysis on nitrate medium (80). Deficiency of isocitrate lyase on acetate medium; see citations in reference 1088. When fl A and fl a strains are inoculated separately on crossing medium in plates, a double line of perithecia forms where they meet, similar to that accompanying barrage in Podospora (410, 414). fl ascospores from certain fl x fl+ crosses often germinate spontaneously (1127; N. B. Raju, personal communication). Allele C-1835 was called acon (717, 812).	IIR	B